Explosion proof container plug



Oct. 3, 1961 G. T. RIEKE 3,002,648

EXPLOSION PROOF CONTAINER PLUG Filed March 16, 1959 2 Sheets-Sheet 1INVENTOR. GLA'IWV. 7'. R/KE.

wiwmz Oct. 3, 1961 G. T. RIEKE EXPLOSION PROOF CONTAINER PLUG 2Sheets-Sheet 2 Filed March 16, 1959 INVENTOR. 62 czwv 7? R/EKE-3,002,648 EXPLOSION PROOF CONTAINER PLUG Glenn T. Rieke, Auburn, Ind.,assignor to Rieke Metal Products Corporation, Auburn, Ind., acorporation Filed Mar. 16, 1959, Ser. No. 799,812 3 Claims. (Cl. 220-44)This invention relates generally to closures for containers such as cansand drums and more particularly, it relates to a plug closure adapted torelieve internal pressure within containers such as drums, cans and thelike.

This application is a continuation-in-part of my application for UnitedStates Letters Patent Serial No. 734,536 filed May 12, 195 8 forExplosion Proof Container Plug and assigned to Rieke Metal ProductsCorporation, Auburn, Indiana, and now abandoned.

In accordance with conventional practice, containers for highly volatileliquids include plug closures which are screwed into a flange in tightlysealing relation thereto in order to prevent leakage of fluids duringhandling and shipment. Such fluids become highly dangerous whensubjected to high temperatures resulting from fires in warehouses andother storage buildings because they volatilize and create excessivepressures within the containers causing them to explode and spreadquantities of volatile fluids throughout a fire area. Quite naturally,this results in highly disastrous fires.

The principal object of this invention is to provide a plug closurehaving valve structure adapted to seal a container under normalconditions and to relieve internal pressure within the container underabnormal temperature conditions.

A further object of this invention is to provide a plug closure havingvalve structure adapted to seal a container under normal conditions andincluding a means for venting internal pressure within the containerwhen said valve structure operates to unseal the container.

In accordance with this invention there is provided a plug closurecomprising a flanged and threaded member adapted to be screwed into acontainer and having a centrally disposed pressure release aperture, anda valve operatively associated with said aperture for normally closingit and operative at a predetermined pressure within said container toopen said aperture.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claims.

FIG. 1 is a top plan view of the plug closure as provided in accordancewith this invention.

FIG. 2 is a transverse cross section of the structure illustrated inFIG. 1.

FIG. 3 is a transverse cross section of the modified form of theinvention.

FIG. 4 is a cross section taken on line 44 of FIG. 3.

Referring to the drawings, this invention comprises a cupped plug member10 having a peripheral flange 11 and a threaded portion 12 whereby theplug member 10 may be screwed into what is commonly called the flange ofa container such as a drum, can or the like.

Plug member 10 is provided with a pressure relief aperture 14 whichcommunicates with the interior of the container to which the plug memberis afiixed. For closing aperture 14 under normal temperature conditions,there is provided a cupped valve 15 and a sealing washer 16 so disposedas to prevent escape of fluid through aperture 14.

Valve 15 is retained in its sealing position by means of a springretaining member 17 Welded to member 10 or otherwise aflixed thereto atspaced points such as 18 and compressing a coil spring 19 intoengagement with valve States Patent 15. Spring 19 may be designed torespond to predetermined pressures within a container of the order of 14to 18 lbs. per square inch, thereby to permit valve '15 to move out ofsealing engagement with member 10. Retainer 17 is provided with anaperture 20 so that gases from within the container may escape throughaperture 14 and around the edges of valve 15 and out through theaperture 20. It will be noted that valve 15 has an outer diameterslightly less than the internal diameter of retainer 17, therebypermitting escape of gases. Spring 19 may also be designed to resealvalve member 15 with member 10 at a minimum pressure of the order of 10lbs. per square inch.

FIGS. 3 and 4 illustrate the modification of this inventionwherein theplug member 10, cupped valve 15 and sealing washer 16 are essentiallyidentical to the corresponding members illustrated in FIGS. 1 and 2. Itis found in certain applications of this invention that the sealingwasher 16 may expand when the valve 15 moves upwardly under heavypressure, such expansion being suflicient to seal ofl the venting spacebetween valve 15 and the spring retaining member 17. Thus, the valve 15is not effective to unseal the container to permit flow of gases throughaperture 14, around the edges of valve 15 and out through the aperture20.

In order to provide venting under relatively high pressures themodification of this invention illustrated in FIGS. 3 and 4 is providedwith a spring retaining member 22, the sidewalls of which are formedwith spaced rib portions 23, thereby to provide spaced channels 24 atregular intervals around the circumference of member 22.

In operation, the modification shown in FIGS. 3 and 4 functionssimilarly to that shown in FIGS. 1 and 2 except that even though thesealing Washer 16 may expand into the space between valve 15 andretainer 22, the channels 24 are not sealed ofl by washer 16. Gases fromwithin the container may flow through aperture 14 into the channels 24and outwardly through the aperture 20 in re tainer 22.

From the foregoing description, it will be apparent that this inventionprovides a plug closure which renders a container relativelyexplosion-proof in the sense that rise of external temperature will notcause accumulation of pressure within a container sufficiently high toexplode the container and cause dangerous distribution of volatilefluids. It will be obvious to those skilled in the art that the plugclosure of this invention may be designed to relieve container pressuresat any desired maximum pressures.

The invention claimed is:

1. A pressure relief plug comprising a flanged and threaded plug havinga centrally disposed pressure relief aperture, a cup-shaped springretainer mounted on said plug with its open end facing said aperture andhaving an escape aperture in its bottom, said retainer having inwardlyopening peripheral channels, a cup-shaped valve of smaller diameter thanthat of said retainer and slidably mounted within said retainer inabutment with the surfaces of said plug surrounding said relief apertureto normally close said relief aperture, and a spring compressed betweensaid retainer and said valve for holding said valve in closed positionagainst predetermined maximum pressure.

2. A pressure relief plug comprising a flanged and threaded plug havinga centrally disposed pressure relief aperture, a cup-shaped springretainer mounted on said plug with its open end facing said aperture andhaving an escape aperture in its bottom, said retainer having peripheralchannels opening inwardly and extending axially of said retainer fromthe bottom thereof to the mounting on said plug, a cup-shaped valve ofsmaller 3 diameter than that of said retainer and slidably mountedwithin said retainer, a sealing washer in abutment with the surfaces ofsaid plug and said retainer surrounding said relief aperture to normallyclose said relief aperture and said channels, and a spring compressedbetween said retainer and said valve for holding said valve in closedposition against predetermined maximum pressure.

3. A pressure relief plug comprising a plug having a pressure reliefaperture, a spring retainer mounted on said plug and facing saidaperture, a cup-shaped valve slidably mounted within said retainer, saidretainer having peripheral channels opening inwardly toward said valveand extending along the length of travel of said valve, a sealing washerengaging the surfaces of said plug References Cited in the file of thispatent UNITED STATES PATENTS 1,441,139 Wichner Jan. 2, 1923 2,538,364James et a1. Ian. 16, 1951 2,684,780 Friend July 27, 1954 2,781,778Lisciani Feb. 19. 1957

